Effective String Description of the Confining Flux Tube at Finite Temperature

Abstract

In this review, after a general introduction to the effective string theory (EST) description of confinement in pure gauge theories, we discuss the behaviour of EST as the temperature is increased. We show that, as the deconfinement point is approached from below, several universal features of confining gauge theories, like the ratio Tc/σ0, the linear increase of the squared width of the flux tube with the interquark distance, or the temperature dependence of the interquark potential, can be accurately predicted by the effective string. Moreover, in the vicinity of the deconfinement point the EST behaviour turns out to be in good agreement with what was predicted by conformal invariance or by dimensional reduction, thus further supporting the validity of an EST approach to confinement.

Dual EFT bootstrap: QCD flux tubes

“…In this work we will show how to optimally bound, using a dual formulation, the allowed values of Wilson coefficients or Low Energy Constants (LECs). In order to do so we will focus our attention on the EFT of confining flux tubes [49,50], see also [51][52][53] and references there in. This system is very fascinating per se, describing the long strings of confining three and four-dimensional theories [49,54], and features an interesting phenomenology [55,56].…”

Fine corrections in the effective string describing SU(2) Yang-Mills theory in three dimensions

“…(8). It is interesting to note that this equality is not simply a consequence of the SU(2)/Ising correspondence that we are studying here: instead, it is much more general and holds also for D > 3 [8]. As we mentioned above, any spin model with an isolated ground state in the spectrum is described by a modified Bessel function of the same type that appears in the EST description.…”

“…( 10) is dominated by the lowest energy level E 0 and, setting D = 3, we end up with exactly the same expression that we found for the largedistance behavior of the spin spin correlator in the two-dimensional Ising model eq. (8). It is interesting to note that this equality is not simply a consequence of the SU(2)/Ising correspondence that we are studying here: instead, it is much more general and holds also for D > 3 [8].…”

“…Here we will limit ourselves to a brief discussion of the features that are most relevant for our problem. For a general introduction to EST, we refer the reader to the recent reviews [6][7][8].…”

“…This implies that the EST is much more predictive than typical effective theories, and in fact during the past few years its predictions have been be confirmed by many simulations in lattice gauge theories (for recent reviews, see for instance refs. [6][7][8]).…”